The heart is the first organ to form-starting to throb approximately three weeks into fetal development, even before there is blood to pump- and life ends when its beat ceases for good. From birth until death in humans, the heart beats approximately three billion times. The amount of work it performs is mind-boggling. Each heartbeat generates enough force to circulate blood through approximately 100,000 miles of vessels. The amount of blood that passes through an average adult heart in a week could fill a backyard swimming pool.
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